Glands of the Plumb agineae. 243 
cells (Fig. 25). The habit of the seedling and the method of 
attachment of the leaf are illustrative (Fig. 24). 
Mucilage-glands proper have not been satisfactorily deter- 
mined in the axils of the bracts and bracteoles. A very 
remarkable series, however, occurs on the inner face of the 
tubular involucral sheath, so diagnostic of the genus. The 
species hitherto found to display this feature are A. vidgaris , 
A. longiaristata , A. H 'alter i, A. cephalosa , A. plantaginea , 
A. cephalotes , var. bracteata , and A. splendens . It maybe con- 
jectured that the condition in one species will, with but slight 
modification, hold good for all species of Armeria . As in the 
case of the leaf, the glands congregate closely to and are 
restricted to the base of this organ (Fig. 26, c), and there is 
no difference in their structure, except that the base may be 
oftener formed of more cells than four. Mettenian glands 
are numerous on the epidermis of the inside and outside of 
the sheath, and also among the short hairs on the rachis under 
it. If one accepts the hypothesis that the reverted sheath 
originates by peltation of the bracts, the occurrence of these 
mucilage-glands is not difficult to explain. They may be 
thus regarded simply as axillary glands. Armeria cephalotes, 
var. bracteata \ displays a notable abnormality, the place of the 
outer bracts being taken by leaves, while the involucral sheath 
still remains 1 2 . Mucilage-glands occur in the axils of these 
foliar organs — an interesting fact, corroborative of the hypo- 
thesis just stated. 
Limoniastrum. 
The leaves of Limoniastrum monopetalum (Fig. 9) clasp the 
stem closely and completely, forming a small crescentic trough 
in the axil, where, in the living specimen, the secretion is 
easily seen. Mucilage-glands are present there in consider- 
able numbers. They are characterised by the basal cells 
being larger than usual. In the present connection L. Guyoni- 
1 Gardeners’ Chronicle, vol. xx, 1883, Fig. 34, p. 213. 
2 See also Armeria plantaginea , Sowerby’s English Botany, 3rd ed., vol. vii, 
p. 159, PI. MCLIV. 
